The present invention relates to a nonlinear editing method, a nonlinear editing apparatus, a program, and a recording medium storing the program, and particularly to a nonlinear editing method, a nonlinear editing apparatus, a program, and a recording medium storing the program that enable intuitive editing operation using a graphical user interface displayed on a display device.
Nonlinear editing refers to creation of desired moving-image contents (broadcasting video contents for a broadcasting program or the like and video contents for personal use) by appropriately selecting a moving-image material and an audio material or materials including both a moving-image material and an audio material (hereinafter referred to simply as “material”) stored on a hard disk, joining the materials together, and giving the materials various rendering effects.
Because of advantages of nonlinear editing such as being capable of finer editing by a frame unit as compared with conventional linear editing using a magnetic tape medium, nonlinear editing has become popular not only for business use of broadcasting stations, postproduction and the like but also now for personal use at school, home and the like against a background of the spread of high-performance personal computers and digital video cameras and the spread of nonlinear editing packaged software that is easy to use and operates on the personal computers.
MediaStudio Pro (trademark), for example, is known as nonlinear editing packaged software that operates on a general-purpose personal computer (hereinafter referred to simply as “nonlinear editing software”). The software includes an editing tool referred to as VideoEditor, which displays a graphical editing window on a screen of the personal computer and thus provides an editing environment with excellent intuitive operability.
FIG. 7 is a diagram showing a part of the editing window (particularly a track editing area). The track editing area 101 is formed by a plurality of (n in FIG. 7) tracks T1 to Tn having an axis of abscissas as a time line 102. A user arranges, on the tracks T1 to Tn, graphic objects referred to as “clips” indicating materials (source files) selected on the basis of intended editing, and thereby performs nonlinear editing.
In the example shown in FIG. 7, a clip C1, a clip C2, and a clip C3 are arranged in that order from the left on the first track T1, and a clip C4, a clip C5, and a clip C6 are arranged in that order from the left on the second track T2. Supposing for convenience that the first track T1 is a video track and the second track T2 is an audio track, the clip C1, the clip C2, and the clip C3 arranged on the track T1 each represent a video material, and the clip C4, the clip C5, and the clip C6 arranged on the second track T2 each represent an audio material.
Thus, in this case, it is possible to obtain a combined output (nonlinear editing output) of a video material (the clip C1, the clip C2, and the clip C3) and an audio material (the clip C4, the clip C5, and the clip C6) sequentially reproducible along the time line 102.
Such nonlinear editing requires various editing operations such as rearranging materials, changing length of a material, changing audio level and the like. Taking the editing window shown in FIG. 7 as an example, the rearranging of materials can be performed by changing positions of the clips C1 to C6. The changing of the length of materials can be performed by changing length of the clips C1 to C6 (length in a horizontal direction of the graphic objects). These editing operations are so devised that the editing operations can be performed intuitively by using a pointing device such as a mouse or the like. Specifically, a clip can be moved by dragging and dropping the entire clip, and the length of a clip can be changed by dragging a left edge or a right edge of the clip.
On an audio track, audio level adjustment for matching levels of two adjacent clips with each other, removing undesired sound and the like is required.
FIG. 8A is a diagram showing one audio clip (clip C4 for convenience) disposed on an arbitrary audio track (track T2 for convenience). A line object 103 for display of audio level, which object indicates 0% at a lower edge of the clip C4 and 100% at an upper edge of the clip C4, is displayed on the clip C4. Both ends of the line object 103 are provided with control point objects 104 and 105 of a given shape (small square in the figure).
The control point objects 104 and 105 can be moved (dragged) in a vertical direction independently. When the control point objects 104 and 105 are dragged in an upward direction (direction of 100%), the audio level is increased, whereas when the control point objects 104 and 105 are dragged in a downward direction (direction of 0%), the audio level is decreased. The line object 103 changes a gradient of a straight line thereof according to the movement (drag) of the control point objects 104 and 105, thereby making it possible to intuitively perceive change of the audio level on the time axis in a visualized form.
FIG. 8B illustrates a first example of control of the audio level. In this example, a new control point object 106 is added to the line object 103, and the position of the control point object 105 situated at the right edge of the clip C4 is lowered to substantially 0%. According to this example, the audio level during reproduction of the clip C4 is maintained at substantially 50% in a range from the control point object 104 to the control point object 106, and is linearly decreased to substantially 0% in a range from the control point object 106 to the control point object 105.
Such audio level control (first example) is used for smooth connection to a subsequent audio clip in the case of a BGM (background music) sound source, for example.
FIG. 8C illustrates a second example of control of the audio level. In this example, new control point objects 107, 108, and 109 are added to the line object 103, and the position of the control point object 108 is lowered to substantially 0%. According to this example, the audio level during reproduction of the clip C4 is maintained at substantially 50% in a range from the control point object 104 to the control point object 107, linearly decreased to substantially 0% in a range from the control point object 107 to the control point object 108, linearly increased to substantially 50% in a range from the control point object 108 to the control point object 109, and maintained at substantially 50% in a range from the control point object 109 to the control point object 105.
Such audio level control (second example) is used when sound unnecessary for reproduction such for example as noise or the like is included in a specific portion (around the control point object 108 in the example shown in FIG. 8C) of the clip C4, for example.
The conventional nonlinear editing software described above is so devised that an editing parameter defined on an arbitrary clip, or an editing parameter such for example as the audio level or the like is stored as information specific to the clip integrally with the clip. When the clip is changed for another clip, for example, an editing parameter of the clip after the change is reset to an initial value.
(1) Such a device has the following problem inherent therein. When the same editing parameter is desired to be applied to the clip after the change, the operation of setting the same editing parameter needs to be repeated, which takes time and trouble.
A case where “the same editing parameter is desired to be applied to the clip after the change” is a case such for example as the foregoing first example. In the first example, the audio level after the control point object 106 is linearly decreased. This operation is a so-called fade-out operation. A fade-out is often used for smooth connection between clips of BGM sound sources and the like. Even when an arbitrary BGM clip is changed for another BGM clip, a fade-out is not removed in general.
(2) A method conceivable for solving the above problem is for example setting an editing parameter not as information specific to a clip but as information specific to a track where the clip is situated. This method does not cause the above problem because the editing parameter remains on the track as it is even when the clip is changed.
However, with this method, when the same editing parameter is desired not to be applied to the clip after the change, for example when another clip without noise is substituted in the audio level control effected to remove noise as in the foregoing second example, the editing parameter for removing noise is of course not needed. Therefore, another operation of resetting the editing parameter to an initial value is required, which again takes time and trouble.